Stage IIA breast cancer refers to the lesion <2cm with <3 lymph nodes metastasis, or lesion 2~5cm without lymph node metastasis, which belongs to the earlier stage of breast cancer. Breast cancer is mainly staged according to TNM. t refers to the size of the primary lesion, T1 is tumor <2cm, T2 is tumor 2~5cm. n refers to the lymph node status, N0 is no lymph node metastasis, N1 refers to palpable lymph node enlargement but mobile or pathology refers to 1~3 axillary lymph node metastasis. m0 is no distant metastasis. Stage IIA breast cancer mainly includes T1N1M0 and T2N0M0, i.e., breast cancer lesions of 2-5cm without lymph node metastasis, or lesions <2cm with 1-3 axillary lymph node metastasis. Stage IIA breast cancer belongs to the early stage, with high cure rate, and most of them can choose surgical treatments such as breast-conserving surgery, modified radical mastectomy, etc., and adjuvant chemotherapy, radiotherapy and endocrine therapy. Patients are advised to keep a positive mindset and get treatment as early as possible, and they can choose the appropriate treatment plan according to their own conditions, personal wishes and needs.